Condition Analysis
AI-powered assessment using site data and 14-day weather history
Ilkley Cow and Calf has had 4 consecutive dry days following only trace precipitation, with the last meaningful rain (4.6mm) falling on August 5th — nine days ago. Combined with warm temperatures up to 32°C, low humidity (53–66%), strong winds, and the south/south-west aspect, the gritstone should be thoroughly dry and in excellent condition today.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and surrounding blocks are fully exposed on open moorland with a S/SW aspect, meaning they receive excellent solar radiation and wind exposure for rapid drying.
- Seepage can persist at the base of the main Cow buttress and in cracks on north-facing sides even after the main faces have dried — check these areas before committing.
- The recent spell of very warm weather (29–32°C on Aug 12–13) with low humidity will have driven moisture out of even deep pore structures in the gritstone.
- Heavy rain is forecast for August 18th (12.9mm) — climbers planning a visit later this week should be aware conditions will deteriorate significantly from Monday onwards.
Reasoning
The last significant rain was 4.6mm on August 5th — nine days ago — followed by only trace amounts (0.1mm on Aug 7 and Aug 10), and the rock has had four fully dry days including an exceptional warm spell peaking at 32°C, so internal moisture levels should be negligible.
The S/SW aspect, exposed moorland setting, sustained westerly winds (13–21 km/h), and warm temperatures (up to 32°C) with low humidity (53–66%) have provided far more than the minimum 24–48 hours of drying needed after the light recent precipitation.
With nine days since any meaningful rainfall and excellent drying conditions, the gritstone should be at full compressive strength with no elevated risk of hold breakage or grain loosening.
Mid-August is prime summer climbing season with long days, warm temperatures, and no freeze-thaw concerns; conditions are near-optimal for gritstone.
Contributing Factors
5
Four consecutive fully dry days and nine days since the last meaningful rain (4.6mm on Aug 5) provide ample drying time well beyond the 48-hour guideline.
Temperatures reached 29–32°C on August 12–13, driving deep evaporation from pore structures in the gritstone.
Average humidity of 66% over the last week combined with sustained winds of 13–21 km/h on an exposed moorland site significantly accelerates drying.
South and south-west facing rock receives excellent solar radiation throughout the day, making this one of the fastest-drying gritstone venues.
Light rain (2.4mm) is forecast for August 17 followed by heavy rain (12.9mm) on August 18, which will end the current dry spell but does not affect today's conditions.
Recommendations
3
- Conditions are excellent for climbing today and should remain so through August 16 — make the most of this dry window before rain arrives.
- Check the base of the main buttress and any north-facing crack systems for residual seepage before climbing those specific lines.
- Plan any weekend climbing for Saturday (Aug 15–16) as heavy rain forecast for Monday August 18 will require at least 48+ hours of drying afterwards.
Previous Analyses
Likely Safe to Climb
90%
2 days ago
Conditions at Ilkley Cow and Calf are excellent. The last meaningful rain was 4.6mm on August 5th — over a week ago — followed by only trace amounts, and the crag has benefited from three fully dry days, warm temperatures up to 33°C today, low humidity (52%), and strong SW winds on an exposed, south-facing site. The rock should be thoroughly dry.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and main buttresses face S/SW and are fully exposed to wind and sun, making them among the fastest-drying gritstone surfaces in the area.
- Lower sections and the north-facing sides of the Calf boulder can retain moisture longer — check these areas if targeting problems there.
- The open moorland setting means the crag is highly exposed to weather; heavy rain forecast for August 17th (27.3mm) will require significant drying time afterwards.
- Cow and Calf can get extremely busy on warm summer weekends — consider visiting early or on weekdays for a better experience.
Warnings
1
- Heavy rain (27.3mm) is forecast for August 17th — do not climb that day and allow adequate drying time afterwards.
Reasoning
The last significant rain was 4.6mm on August 5th, over a week ago, with only trace precipitation since (0.9mm on Aug 6, 0.1mm on Aug 7 and Aug 10), and three consecutive fully dry days leading into today — internal moisture should be fully dissipated.
The S/SW aspect and exposed position have received excellent solar radiation and consistent winds (13–22 km/h from W/SW), with today reaching 33°C and humidity as low as 24%, providing outstanding drying conditions.
With over a week of effective drying since the last notable rain and warm summer temperatures, the rock should be at or near its full dry strength with negligible risk of hold breakage.
Mid-August is peak summer season with long days, warm temperatures, and no freeze-thaw concerns — ideal conditions for gritstone climbing.
Contributing Factors
5
Over a week since the last meaningful rain (4.6mm on Aug 5), with only trace amounts since, providing ample drying time well beyond the 48-hour guideline.
Temperatures reaching 33°C with humidity dropping to 24% provide outstanding evaporative drying power.
Consistent winds of 13–22 km/h on this fully exposed moorland site significantly accelerate surface and subsurface drying.
The south and south-west facing rock receives maximum solar radiation throughout the day, enhancing drying at depth.
27.3mm of rain is forecast for August 17th, which will reset drying conditions but does not affect the current window.
Recommendations
3
- Conditions are excellent today and through the next three days — make the most of the dry window before heavy rain arrives on August 17th.
- Check shaded or north-facing faces of boulders at the base, which may occasionally retain dampness even in good conditions.
- Avoid climbing on August 17th and allow at least 48–72 hours of dry weather after the forecast heavy rain before returning.
Likely Safe to Climb
88%
3 days ago
Conditions at Ilkley Cow and Calf are good for climbing today. The last meaningful rain was 4.6mm on August 5th (7 days ago), followed by only trace amounts, and the south/south-west exposed aspect with strong winds has provided excellent drying conditions. Today's hot, dry weather (29°C, humidity dropping to 29%) further confirms the rock should be thoroughly dry.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and surrounding problems are fully exposed to sun and wind on their south-facing aspects, which dry fastest, but north-facing sides and shaded recesses around the base can hold moisture longer.
- Seepage lines can persist on the main Cow crag after wetter spells, particularly on lower sections where water drains down from the moorland above — always check these areas visually.
- The open moorland setting at 260m means conditions can change quickly; afternoon thunderstorms in summer heat are possible even when the morning looks perfect.
- The crag is very popular and easily accessible — weekend crowds can mean queues on classic problems, and polished holds on popular lines are more friction-sensitive when even slightly damp.
Reasoning
The last significant rain was 4.6mm on August 5th, seven days ago, with only trace precipitation since (0.9mm on the 6th, 0.1mm on the 7th and 10th); internal moisture should be fully dissipated given the extended drying window.
The south/south-west aspect and exposed position have allowed strong solar radiation and persistent westerly winds (14–21 km/h average over the past week) to drive thorough evaporation over seven days, far exceeding the 48-hour guideline for light rain.
With seven days of effective drying after only light-to-moderate rain, the rock should have returned to full compressive strength with no meaningful structural risk from residual moisture.
Mid-summer conditions are ideal for gritstone climbing — long days, warm temperatures, and no freeze-thaw risk; today's heatwave conditions (29°C) provide exceptional drying but may reduce friction on polished holds.
Contributing Factors
5
Seven days since the last meaningful rain (4.6mm on Aug 5), with only trace amounts since, providing ample drying time well beyond the 48-hour minimum.
The south/south-west aspect and fully exposed moorland position maximise solar radiation and wind exposure, accelerating drying significantly.
Today's forecast of 29°C with humidity dropping to 29% and clear skies provides excellent conditions that will have fully dried any lingering surface moisture.
Only 12.8mm total over 28 days indicates no prolonged saturation period, meaning the rock was never deeply waterlogged.
Temperatures approaching 30°C can soften rubber on climbing shoes and reduce friction on polished gritstone holds, particularly in direct afternoon sun.
Recommendations
3
- Conditions are good — climb with confidence today, but check shaded or north-facing aspects of the Calf boulder and any seepage-prone sections before committing.
- Consider climbing in the morning or late afternoon to avoid the hottest part of the day when shoe rubber friction may be reduced on polished holds.
- Be aware that rain is forecast from August 16th — plan any ambitious projects for the next few days while the dry window lasts.
Likely Safe to Climb
88%
5 days ago
Ilkley Cow and Calf should be in excellent climbing condition today. The most significant rain was 4.6mm on August 5th, followed by only trace amounts (0.9mm and 0.1mm), with three full dry days since and good drying conditions on an exposed, south-facing crag in summer.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and main crag face S/SW and are fully exposed to wind, making them among the fastest-drying gritstone venues in Yorkshire.
- Seepage can persist in the back of the Calf cave and at the base of some lower walls even when the main faces are bone dry — check these areas before committing.
- The open moorland setting means conditions can change quickly; afternoon convective showers are possible in summer even when not forecast.
- Weekend crowds can be significant — the easy access and car park make this a popular venue, so plan for busy conditions on the classic problems.
Reasoning
The last meaningful rain was 4.6mm on August 5th (5 days ago), followed by only 0.9mm on the 6th and a trace 0.1mm on the 7th, with three completely dry days since — the rock should be thoroughly dry internally.
The S/SW aspect and exposed position at 260m have provided excellent drying conditions, with sustained winds of 16–21 km/h and summer temperatures in the high teens to low twenties, comfortably exceeding the 48-hour guideline for light-to-moderate rain.
With five days of drying since the 4.6mm event and only trace rain since, internal moisture levels should be negligible and there is no meaningful structural risk from residual dampness.
Mid-summer conditions are ideal for gritstone climbing — long days, warm temperatures, and no freeze-thaw risk; this is the prime season for Ilkley.
Contributing Factors
5
The 4.6mm event on August 5th was five days ago, well beyond the 48-hour minimum drying guideline for moderate rain on exposed gritstone.
The S/SW aspect and exposed moorland position maximise solar radiation and wind drying, making this one of the fastest-drying gritstone crags in the area.
Winds have been consistently 16–27 km/h over the past few days, significantly accelerating evaporation from the rock surface and interior.
Humidity has averaged around 67% over the last three dry days, which is acceptable for drying though not exceptionally low; today's afternoon humidity drops to the mid-40s.
The 0.9mm on the 6th and 0.1mm on the 7th were negligible amounts that would not have significantly re-wetted already-drying rock.
Recommendations
3
- Conditions are good for climbing — head out and enjoy the afternoon when humidity is at its lowest (mid-40s) and temperatures peak near 20°C.
- Do a quick visual and touch check at the base of the crag and in any sheltered recesses, as these areas dry last even in otherwise perfect conditions.
- The forecast looks excellent through midweek with warm, dry weather building, so this is a great window for ticking projects.
Marginal — Assess Conditions
72%
5 days ago
The most significant rain was 4.6mm on August 5th, followed by 0.9mm on the 6th and a trace 0.1mm on the 7th, giving roughly 2 full dry days with decent temperatures and moderate wind. The south/south-west aspect and exposed position at Cow and Calf aid drying considerably, but the cumulative recent rainfall and humidity in the mid-70s mean a visual check on arrival is prudent before committing to climb.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and lower buttresses can retain seepage at their bases even when upper faces appear dry — check the base of the rock carefully.
- The south/south-west aspect and fully exposed moorland position make this one of the faster-drying gritstone venues in Yorkshire.
- Cow and Calf sees heavy foot traffic at weekends which can compact ground moisture indicators — use the rock itself (touch test on shaded faces) rather than path conditions to judge dampness.
- North-facing arêtes and any features tucked behind the main Calf boulder will dry significantly slower than the prominent south-facing walls.
Warnings
1
- Do not climb on any face that feels cool or damp to the touch — gritstone can lose 30%+ of its compressive strength while appearing surface-dry.
Reasoning
The 4.6mm on August 5th was the most significant event, followed by lighter rain on the 6th and a trace on the 7th; with only ~2 full dry days elapsed, internal moisture likely remains in porous gritstone despite surface drying.
The south/south-west aspect and exposed position with winds of 19–23 km/h from the west/south-west provide good drying conditions, and temperatures of 18–24°C are favourable, meaning the lighter rainfall component has likely dried but the 4.6mm event may still leave residual internal moisture.
At approximately 2 days since the last meaningful rain (5.6mm over Aug 5–6), there is a moderate risk that internal moisture could reduce hold strength on gritstone, particularly on features that don't receive direct sun.
Mid-summer conditions are broadly favourable with long daylight hours, warm temperatures, and no freeze-thaw risk; this is the best time of year for drying.
Contributing Factors
5
A total of 5.6mm fell on August 5–6, with a trace on the 7th, providing only about 2 full dry days which is borderline for gritstone after moderate rain.
The fully exposed south/south-west facing aspect receives excellent solar radiation and wind, making Cow and Calf one of the fastest-drying gritstone crags in the area.
Winds of 19–23 km/h from the west and south-west over the past two days actively move moist air from the rock surface, significantly accelerating evaporative drying.
Average humidity around 74% over the past week slows the drying rate compared to truly dry spells, meaning evaporation is less efficient than ideal.
Temperatures of 18–24°C over the drying period are well above the threshold where drying slows significantly, aiding moisture removal from porous gritstone.
Recommendations
3
- Visually inspect the rock before climbing — touch shaded faces and check for any darkening or cool-to-touch patches, especially at the base of the Calf boulder.
- Prioritise the prominent south-facing walls and upper sections which will have dried fastest; avoid north-facing arêtes and sheltered corners today.
- If any dampness is detected, wait — the forecast shows continued dry weather through mid-August so conditions will only improve over the coming days.
Marginal — Assess Conditions
62%
6 days ago
Recent light rain on Aug 5–6 (5.5mm combined) with a trace on Aug 7, followed by only one full dry day today with good conditions (23.7°C, 64% humidity, moderate wind). The south/south-west aspect and exposed position aid drying, but only one dry day after several days of light-to-moderate rain means the rock may not be fully dry internally.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and main crag faces are south/south-west facing and fully exposed to wind, meaning they dry faster than most gritstone venues — but sheltered areas beneath overhangs and at the base can retain moisture longer.
- The open moorland setting means the ground around the crag can give a useful indicator: if the peat and soil at the base is still damp, the rock likely retains internal moisture.
- The 4.6mm on Aug 5 was the heaviest single-day rain in weeks and came with high humidity (85%), which would have saturated surface layers significantly before the lighter follow-up rain on Aug 6.
- Being at 260m on Ilkley Moor, evening temperatures can drop notably (down to 6°C last night), which slows overnight drying despite good daytime conditions.
Warnings
1
- Light rain (1.0mm) is forecast for tomorrow Aug 9, which will reset drying progress — plan accordingly if conditions are marginal today.
Reasoning
The most significant wetting event was 4.6mm on Aug 5 followed by 0.9mm on Aug 6 and a trace (0.1mm) on Aug 7, meaning the rock has had only about 1.5 genuinely dry days to recover from a cumulative ~5.6mm of rain over three days.
Today's conditions are excellent for drying (23.7°C, 64% humidity, moderate westerly wind on an exposed S/SW crag), but the guideline minimum of 24–48 hours after light rain is only just being met, and the preceding days were cooler (15–18°C) with moderate humidity (67–78%).
With only marginal drying time, internal moisture could still reduce grain-cement bond strength, posing some risk of hold breakage on gritstone — particularly on less-trafficked or fragile features.
Mid-summer conditions are generally favourable with long daylight hours and warm temperatures, and there is no freeze-thaw risk at this time of year.
Contributing Factors
6
A total of 5.5mm fell on Aug 5–6 with a further trace on Aug 7, providing only ~1.5 effective drying days before today.
The south/south-west facing, fully exposed position maximises solar radiation and wind-driven evaporation, significantly accelerating drying.
23.7°C with 64% humidity and moderate westerly wind provides strong drying conditions through today.
Aug 6–7 were only 15–18°C with humidity around 67–78%, limiting drying efficiency on those days.
Winds of 19–32 km/h over the past several days on this exposed site significantly aid surface evaporation.
Last night dropped to 6°C which greatly slows overnight drying and can cause condensation on the rock surface.
Recommendations
3
- Visit later in the day after the rock has had maximum sun and wind exposure; check the base of the crag and ground moisture as an indicator of internal rock condition.
- Prioritise the most exposed, south-facing walls and the upper sections of the Calf boulder which will have dried fastest; avoid low-lying or sheltered features.
- If any dampness is visible or the rock feels cold and clammy to the touch, wait — tomorrow (Aug 9) brings more rain so Aug 11 onwards is a better window.
Marginal — Assess Conditions
72%
7 days ago
The most recent significant rain was 4.6mm on August 5th followed by 0.9mm on August 6th, with today (August 7th) being the first fully dry day. While the S/SW aspect and exposed, windy position at Cow and Calf aid drying considerably, only one full dry day has passed since the last meaningful rainfall, which is below the recommended 48-hour minimum for porous gritstone. Climbers should visually assess conditions on arrival.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and main buttresses face S/SW and are fully exposed to wind across Ilkley Moor, making them among the faster-drying gritstone venues in Yorkshire.
- Seepage can persist at the base of the main Cow buttress and in cracks/breaks on the Calf boulder longer than exposed faces appear dry — check these areas carefully.
- The site saw a broader wet spell from July 25–28 (4.8mm total) followed by intermittent light showers through August 6th, meaning the rock has had limited opportunity for deep drying over the past two weeks.
- Open moorland setting means morning dew can re-wet surfaces even on dry days, particularly on cooler mornings below 10°C like today's 9.3°C minimum.
Warnings
1
- Only one full dry day has passed since 4.6mm of rain on August 5th — gritstone surfaces may appear dry while the interior remains damp, risking hold breakage and permanent route damage.
Reasoning
The rock received 4.6mm on August 5th and 0.9mm on August 6th after an already damp period, and has had only one full dry day (today) with moderate wind and 70% humidity — the surface is likely drying but internal moisture may persist.
The S/SW aspect and strong westerly winds (20–32 km/h over recent days) significantly accelerate surface drying, but with only ~24 hours of dry weather since the last rain and humidity around 70%, full drying through the porous gritstone matrix is unlikely to be complete.
Summer temperatures (15–18°C) mean no freeze-thaw risk, but residual internal moisture from the recent wet spell could still reduce grain cohesion and increase the risk of hold breakage on this coarse Millstone Grit.
Mid-summer conditions are generally favourable with long days and reasonable temperatures, though this has been a cooler, damper spell than typical for early August.
Contributing Factors
5
4.6mm fell on August 5th with a further 0.9mm on August 6th, and only one dry day has elapsed since — below the recommended 48-hour drying minimum for gritstone.
The S/SW facing, fully exposed position on open moorland with consistent 20+ km/h westerly winds provides excellent drying conditions relative to most gritstone venues.
The two weeks prior included multiple small rain events totalling 12.6mm over 28 days, limiting the rock's opportunity for deep internal drying.
Humidity at 70% today is not ideal but not critically high, allowing slow but meaningful evaporation especially with the 20.5 km/h wind.
Temperatures around 17–18°C with no frost risk mean reasonable evaporation rates and zero freeze-thaw concern.
Recommendations
3
- Wait until tomorrow (August 8th) when a second full dry day with warmer temperatures (23.6°C) and lower humidity (66%) will significantly improve confidence — visually assess on arrival.
- If visiting today, check the base of routes and the ground at the foot of the crag: if the soil or peat is still damp, assume the rock retains internal moisture and do not climb.
- Avoid low-lying or north-facing sections of the buttresses and any areas with visible seepage or dark patches, even if main faces appear dry.
Do Not Climb
55%
9 days ago
Recent rain on 4th–6th August (totalling ~7.8mm over three days, including 5.1mm on the 5th) with today's light showers means the gritstone has not had adequate drying time. Although the exposed S/SW aspect and strong westerly winds will help, the rock is likely still holding internal moisture and conditions are not yet safe for climbing.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and main buttresses face S/SW and are well exposed to the prevailing westerly winds, which is the best possible combination for drying — but even so, 5.1mm on the 5th plus today's 1.1mm means less than one full dry day has elapsed.
- Seepage can persist at the base of the Calf boulder and in the horizontal breaks on the main quarried walls, especially after cumulative wet spells like the past few days.
- The open moorland setting at 260m means dew and overnight moisture are common even in summer, and humidity has been elevated (74% average over the past week), slowing the drying process.
- The prior wet spell from 25th–28th July (~4.8mm) means the rock entered this latest rain event already carrying residual moisture from barely two weeks of intermittent dampness.
Warnings
2
- Do not climb today — rain fell this morning and the gritstone is wet; climbing risks permanent hold damage.
- The rock surface may appear dry before the interior has adequately dried — surface appearance is unreliable after recent rain on porous gritstone.
Reasoning
With 5.1mm on 5th August and 1.1mm today (6th), plus scattered light rain on 1st, 3rd, and 4th August, the gritstone is almost certainly still holding significant internal moisture despite any surface drying.
Strong westerly winds (25–32 km/h) and the S/SW aspect will aid evaporation, but with rain falling as recently as this morning and humidity at 77%, less than one effective drying day has passed since the last meaningful precipitation.
Millstone Grit loses significant compressive strength at low saturation levels, and the cumulative rainfall over the past 48 hours (6.2mm) means holds are at elevated risk of breakage — climbing now risks permanent damage.
Summer conditions are generally favourable for drying, but August can bring persistent frontal rain and the current unsettled spell with above-average humidity is slowing recovery.
Contributing Factors
7
1.1mm of rain fell today including early morning showers, resetting the drying clock.
5.1mm fell on the 5th in strong winds, thoroughly wetting the rock less than 48 hours ago.
8.4mm over the past 7 days across multiple events means the rock has had little chance to fully dry between wettings.
Average humidity of 74% over the past week reduces evaporative drying efficiency.
Sustained westerly winds of 20–32 km/h at this exposed site significantly aid surface drying.
South and south-west facing rock receives strong solar radiation in August, accelerating evaporation when skies clear.
Humidity drops to 58% this afternoon with moderate winds, providing some useful drying hours.
Recommendations
3
- Wait at least until the afternoon of 8th August, allowing two full dry days after today's last rain, before considering climbing.
- On arrival, check the base of the Calf boulder and horizontal cracks for dampness — if the ground at the crag foot is moist, the rock is still wet internally.
- If visiting on the 8th, prioritise steep or overhanging problems on the Calf boulder which shed water fastest, and avoid slabby or low-angle routes which retain moisture longest.
Do Not Climb
95%
11 days ago
Today has seen significant rainfall (13.3mm) including heavy showers forecast through the afternoon and evening, making the gritstone thoroughly wet. The rock will need substantial drying time, and further rain is forecast tomorrow (5.1mm) and on the 6th (0.9mm), prolonging the wet period.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and main buttresses face S/SW, which normally aids drying, but the sustained rain today and tomorrow will saturate the porous gritstone deeply — surface drying may mislead.
- The exposed moorland position means strong westerly winds forecast from the 5th onwards (29–34 km/h) will help accelerate surface drying once rain stops, but internal moisture will persist longer.
- Lower sections of the Calf boulder and sheltered faces around the quarry area tend to hold moisture longer than the exposed upper faces.
- The preceding weeks saw light but repeated rain events (25th–28th July, 1st and 3rd August) meaning the rock was never fully bone-dry before today's heavy soaking.
Warnings
2
- Climbing on saturated gritstone risks permanent hold breakage and irreversible route damage — do not climb even if the surface appears dry.
- Heavy rain (up to 5.4mm/hr) is forecast for this afternoon and evening; avoid the exposed moorland during thundery conditions.
Reasoning
Today's 13.3mm of rain, following several light rain events in the past 10 days, will have deeply saturated the gritstone well beyond the critical 1% threshold where significant strength loss begins.
With further rain forecast tomorrow (5.1mm) and light rain on the 6th (0.9mm), meaningful drying cannot begin until the 7th at the earliest; the S/SW aspect and exposed wind will then help, but 48–72 hours of dry weather are needed after heavy rain on porous gritstone.
At current saturation levels the gritstone could lose 10–50% of its compressive strength, creating serious risk of hold breakage and permanent route damage.
Summer temperatures (17–19°C) and longer daylight hours are favourable for drying once rain ceases, but humidity levels remain elevated (70–87%) which slows evaporation.
Contributing Factors
7
13.3mm of rain today, with the heaviest falls (5.4mm in one hour) in the late afternoon, will thoroughly saturate the porous gritstone.
An additional 5.1mm forecast for the 5th prevents any meaningful drying and keeps the rock saturated.
A further 0.9mm on the 6th delays the start of the drying clock to the 7th at the earliest.
Light rain events on 25th–28th July and 1st and 3rd August mean the rock was not fully dry before today's heavy soaking.
Sustained westerly winds of 20–34 km/h from the 5th onwards on the exposed moorland will significantly aid surface drying once rain stops.
South and south-west facing rock will receive good solar radiation during August daylight hours, accelerating drying once skies clear.
Humidity remains elevated at 71–87% through the forecast period, slowing evaporative drying from the rock surface.
Recommendations
3
- Do not climb today or tomorrow — the gritstone is saturated and further rain is imminent.
- The earliest realistic window for climbing is the 8th August after two full dry days, but check the rock carefully on arrival, especially lower sections and sheltered faces.
- If visiting on the 8th or 9th, perform the ground-moisture test at the crag base — if the ground is not sandy-dry, the rock is likely still damp internally.
Marginal — Assess Conditions
60%
12 days ago
A prolonged dry spell through most of July left the rock thoroughly dried out, and recent light rain (totalling ~6mm over the past 10 days) has been minor. Today features a dry, warm afternoon window with low humidity and good wind, but 1mm of rain fell earlier today and light showers are forecast from this evening onward, with unsettled weather continuing through the week. An afternoon session today is plausible if the rock feels dry on arrival, but the outlook is deteriorating.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The Calf boulder and main crag face south/south-west, catching afternoon sun which will aid drying during today's clear midday window.
- The exposed moorland position at 260m means strong westerly winds accelerate drying significantly, but also bring Atlantic frontal rain more readily.
- Seepage can persist at the base of the Calf boulder and in cracks on the main quarry wall even when upper faces appear dry — always check lower sections.
- The site's popularity means any damage from wet climbing is multiplied; local ethics strongly discourage climbing on damp grit.
Warnings
2
- Rain is forecast from 20:00 tonight — do not start long routes or new problems late in the afternoon as conditions will deteriorate.
- The coming week looks persistently unsettled with daily rain; do not assume brief dry spells between showers are sufficient for the rock to dry.
Reasoning
The rock benefited from an exceptional dry spell (nearly three weeks dry from July 6–24), and recent rain has been very light and scattered (1.4mm on Jul 25, 2.3mm on Jul 26, 1.0mm on Jul 27, trace amounts since), so internal moisture levels should be low provided today's 1mm has had time to evaporate.
Today's afternoon conditions — clear skies, 24°C, humidity dropping to 38%, and ~19 km/h wind on an exposed S/SW-facing crag — should dry the light morning moisture within a few hours, and the preceding dry days since July 28's trace rain gave good baseline drying.
Structural risk is low given the extended dry period that preceded recent light showers; the rock should retain most of its strength as cumulative wetting has been minimal.
Mid-summer conditions are generally favourable with warm temperatures and long daylight hours, though the current pattern is turning unsettled with daily light rain forecast through the week.
Contributing Factors
6
Nearly three weeks without rain (July 6–24) thoroughly dried the rock before recent light showers, meaning internal moisture was at a very low baseline.
Approximately 6mm has fallen in scattered light events since July 25, with 1mm today, keeping the surface intermittently wetted though never heavily soaked.
Today's forecast shows clear skies from 10:00–17:00 with temperatures up to 24.6°C and humidity as low as 38%, providing an excellent drying window on this south-facing crag.
Sustained winds of ~19 km/h on the exposed S/SW face will move moist air efficiently, significantly accelerating surface and near-surface drying.
Light rain is forecast every day from August 4–8 (totalling ~8.4mm), meaning conditions will worsen through the week with no sustained drying window.
Showers are forecast from 20:00 tonight (0.7mm total), which will re-wet the rock surface and reset drying for tomorrow.
Recommendations
3
- If climbing today, arrive by midday and assess the rock surface carefully — the afternoon window (11:00–18:00) offers the best drying conditions before evening showers.
- Apply a simple touch test to the rock and check the base of the Calf boulder and crack systems for seepage before committing to climb.
- Given the unsettled forecast for the coming week, today's afternoon may be the last reasonable window for several days — but do not climb if the rock feels anything other than completely dry.
Climbing Outlook